Lead author Mark Peaden from the University of California, Davis said that roads are everywhere. Where tortoises and roads meet, it is inevitable that tortoises will lose.

Even in protected areas like the Mojave National Preserve, several tortoises are killed on roads each year. One technique that land-managers can use to keep tortoises safe is by installing a fence along the roads.

The researchers placed tiny GPS units on tortoises that are found near roads and along the newly installed fencing.

The units recorded the location and temperature of the animals in every 15 minutes for two years.

The findings revealed that the tortoises definitely cross roads, but they do so far less than expected.

Although fencing kept tortoises off roads, some tortoises had difficulties adjusting to a new barrier.

“You can imagine how confused a tortoise must be after living in a place for 20 or 30 years and suddenly there is a barrier in its way,” said co-author Tracey Tuberville from the University of Georgia.

“Managers may have to account for this behavior by designing and installing barrier fencing that minimises pacing or the risk that pacing animals will overheat,” Tuberville added.

Such short-term problems need to be addressed to reap the long-term benefits of fencing.

When tortoises are not barred from crossing roads, the study showed that they tended to cross where desert washes occurred. This helps managers target where to install barrier fencing or road underpasses to make fences most useful.